The M40 is 89 miles long, so we split it into six stretches. Each has its own page with the junctions, the towns they serve, the latest reports and the traffic count for that part of the road.

The six stretches

• Junctions 1 to 4: Beaconsfield and High Wycombe — the London end, the M25 interchange and the busiest traffic on the road.
• Junctions 4 to 7: Stokenchurch and the Chilterns — the original 1967 motorway and the Stokenchurch Gap cutting.
• Junctions 7 to 9: Oxford — Thame, Wheatley, the A40 and the A34.
• Junctions 9 to 11: Bicester and Banbury — the A43 and Cherwell Valley services.
• Junctions 11 to 14: Gaydon and Leamington — into Warwickshire, with Warwick services.
• Junctions 14 to 16: Warwick to the M42 — the A46 and the end of the motorway.

The six stretches compared

The busiest main-line count on each stretch, from the Department for Transport road traffic statistics, 2025, in vehicles a day:

Stretch	Busiest count	Where
Junctions 1 to 4	136,403	J1A to J2
Junctions 4 to 7	100,922	J5 to J6
Junctions 7 to 9	92,005	J7 to J8
Junctions 9 to 11	100,293	J9 to J10
Junctions 11 to 14	89,483	J11 to J12
Junctions 14 to 16 and the M42	113,433	J14 to J15

The London stretch is clearly the heaviest, and the Warwick stretch is the busiest north of the Chilterns. The Oxford stretch includes the quietest main-line count on the road, 70,986 between Junctions 8 and 9.

The full junction list

For every junction number in one place, with the roads and towns each one serves, see the map of M40 motorway junctions.

Using a stretch page

Each stretch page shows the reports affecting that part of the M40 above, with the fixed information — what the junctions connect, and how much traffic the Department for Transport counted there in 2025 — underneath. It is the quickest way to check the part of the road you use most.

For the whole motorway at once, see the latest M40 traffic news.

Traffic count figures on this page are from the Department for Transport road traffic statistics, 2025.